High antioxidant lamellar structure Cr2AlC: Dielectric and microwave absorption properties in X band

Generally speaking, thermal stability is the key factor for microwave absorbers (MAs) at high temperature. In this paper, we first propose to apply a novel material called Cr2AlC (CAC) in the high temperature field. The self-made high purity CAC powder prepared by salt bath exhibits good microwave absorption performance and outstanding. Thermogravimetric (TG) analysis indicates the CAC begins to oxidize significantly above 800 degrees C. Moreover, the effective medium theory is adopted to calculate the microwave absorption performance for the CAC/paraffin composite material. We found that the sample with 70 wt% CAC (CAC70) has a minimum reflection loss of -25.09 dB at 11.08 GHz and its effective absorption bandwidth (below -10 dB) is 2.2 GHz (10.2-12.4 GHz) at the thickness of 2.00 mm, which indicates a thin layer of Al2O3 at room temperature will not affect the entry of electromagnetic waves and internal electrical losses. The high anti-oxidation layered structure CAC provides an opportunity to expand microwave absorption in high temperature applications. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This paper introduces a novel material Cr2AlC (CAC) for high temperature microwave absorption, which exhibits good performance. Experimental results show that the sample with 70 wt% CAC has the best microwave absorption performance, with an absorption bandwidth of 2.2 GHz.